D&D 5E SPIRIT GUARDIANS range clarification

[Hriston]

So when a gargantuan creature casts Globe of invulnerability, the Globe is wholly inside the creature?

Well, it's wholly within the 20' x 20' space the gargantuan creature controls. The creature itself needn't be as big.

Both that spell, and Spirit Guardians expressly state they create a 10' (or 15' for SG) radius 'around you'. To me that implies (in fact it expressly states) that you measure the radius starting at the outer edge of the creature casting it (or in this case, their space for simplicity) and not some nebulous point inside the creature.

If I were to draw a 10' radius around a sports stadium, I'd have a 10' radius around a sports stadium, and not a 10' circle in the middle of the playing field.

If a spell creates an AoE and has a range of self, then the point of origin for the effect is the creature that casts the spell. If the AoE is a sphere, then the sphere's point of origin (i.e. the creature) is included in (i.e. is not additive to) the sphere's AoE. The radius of a sphere, not its point of origin, defines the size of the sphere.

 

[billd91]

A point does not have a width or length by definition.

In mathematics. This isn’t mathematics. The rules are explicit and clear that the ”point” may be a whole creature. Certainly the rules would supersede the specific definition of point used in mathematics.

 

[Flamestrike]

Well, it's wholly within the 20' x 20' space the gargantuan creature controls. The creature itself needn't be as big.

What if it is that big? Are you saying the Globe appears inside the creature?

If a spell creates an AoE and has a range of self, then the point of origin for the effect is the creature that casts the spell. I

No, the spells I referred to expressly state they create the 10 or 15' radius around you (the caster).

If I draw a 1' radius around a circular power or telegraph pole (that itself has a radius of 2'), is the circle I drew inside the pole, or 1' outside of it?

 

[Voadam]

In mathematics. This isn’t mathematics. The rules are explicit and clear that the ”point” may be a whole creature. Certainly the rules would supersede the specific definition of point used in mathematics.

5e generally says go with natural language definition of words in the game, so radius would be the normal definition of radius, not a specific rule technical definition that is contrary to the natural language definition.

 

[Voadam]

No, the spells I referred to expressly state they create the 10 or 15' radius around you (the caster).

If I draw a 1' radius around a circular power or telegraph pole (that itself has a radius of 2'), is the circle I drew inside the pole, or 1' outside of it?

By definition a 1' radius circle can not be drawn surrounding the 2' radius pole. Definitionally.

A circle extending 1' further outside of the 2' radius pole is a 3' radius circle.

 

[Flamestrike]

5e generally says go with natural language definition of words in the game, so radius would be the normal definition of radius, not a specific rule technical definition that is contrary to the natural language definition.

Use plain language then.

If I draw a 10' radius around an (object or person), do I measure from inside the object or person, or outside of the object or person?

Natural language suggests the 10' radius is drawn from the outside of the object or person, seeing as it avoids the absurdity of a 10 radius around something that is bigger than 20' across, not have a 10' radius around them, but instead have the 10' circle be wholly inside of them.

Like assume I (right here and now) instruct you to go away and draw for me a '10' radius around your house'.

Using plain natural language, do you then draw a 10' radius circle inside your house, or around the outside of it?

 

[Flamestrike]

By definition a 1' radius circle can not be drawn surrounding the 2' radius pole. Definitionally.

A circle extending 1' further outside of the 2' radius pole is a 3' radius circle.

I didnt ask you to draw a 1" radius circle, ignoring the pole though, did I?

I asked you to draw a 1" radius around the pole.

 

[Flamestrike]

@Voadam

Imagine you're reading the following text of an adventure:

This 300' wide circular room contains a 30' radius (60' diameter) circular pillar in the middle of the room, that extends all the way to the roof. Magical energy crackles from the pillar. There are no other exits from this room.

The pillar is trapped, and any creature that enters within a 20' radius of the pillar is dealt (20d6 force damage, Dex save DC 15 for half).

Is it your position that to trigger the above trap, one would need to tunnel inside the pillar at least 10 feet, or that you trigger it once you get within 20' of the pillar?

 

[DND_Reborn]

The pillar is trapped, and any creature that enters within a 20' radius of the pillar is dealt (20d6 force damage, Dex save DC 15 for half).

Take out the word "radius" and you're good.

WotC should have done the same with spells like Spirt Guardians. If you are within X feet of something, it's shape doesn't matter and the result makes more sense.

This also can more easily be translated to grids for tabletop IMO.

 

[Flamestrike]

Take out the word "radius" and you're good.

The key word here is 'around'.

If I draw something AROUND something else, I'm not drawing it potentially INSIDE that thing.

If a spellcasting variant Gargantuan Ancient Dragon casts Globe of Invulnerability, the Globe appears 10' AROUND the Dragon, just like the spell says it does.

Not as a 10' radius globe with 90 percent of the dragon sticking out of it.